Infectious pathogens often cause significant economic losses and frequently cause serious public health concerns throughout the world, such as the massive outbreak of a food-borne pathogen Escherichia coli O157:H7, which occurred in Japan in 1996 (Michino et al. Am. J. Epidemiol. 1999. 150:787-796). Over the past decades, several methods, such as polymerase chain reaction (PCR)-based methods, DNA microarrays, DNA sequencing technology and so on, have been employed for efficient pathogen detection with high specificity. Although these DNA-based approaches have been utilized for pathogen identification, they cannot detect pathogenic microorganisms directly. They either depend on expensive and high-precision instruments (e.g., DNA sequencing), or require cumbersome procedures, such as cell lysis, DNA extraction, amplification and purification.
Immunoassays based on the specific interaction between antibody and antigen can be used for direct pathogen detection. Antibodies, however, are more expensive than oligonucleotides and also can easily become denatured and lose their activities to bind to pathogenic microorganisms.
Pathogen detection technology is vital to the prevention and identification of infectious diseases and biodefense threats. There remains a need for simple, rapid, and sensitive assays for multiplexed detection of pathogens or chemicals.